Process of obtaining metals, such as lead or zinc, in an electric furnace.



A.v HELFENSTEIN. i PROCESS 0F OBTAINING METALS SUCH AS LEAD 0R ZINC I N AN ELECTRIC FURNACE.

APPLlcATIoN FILED FEB. 2, |914.

Patented Jan. 11, 1916-.

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.ALOIS HELFENSTEIN, OF VIENNA, AUSTRIA-HUNGARY.

PROCESS OF OBTAINING METALS, SUCH AS LEAD OR ZINC, IN AN ELECTRIC FURNACE.

Specification of Letters Patent.

.Patented Jan. 11,1916.

Application filed February 2, 19111. Serial No. 816,036.

To all whom it may concern Be it known that l, ALois HELFENSTEIN, a citizen of Switzerland, residing at 50 Bastiengasse, Vienna, Austria-Hungary, have invented a new and useful Improvement in Processes of Obtaining Metals, Such as Lead or Zinc, in an-Electric Furnace, of which the following isa specification.

My invention relates to improvements in processes for obtaining metals, such as lead or zinc, etc., in liquid form in electric distillation furnaces; and thev objects of my improveniente are to facilitate and cheapen the obtaining of metal in liquid form, and to reduce the proportion of dust formed.Y

The obtaining of metals such as lead and zinc, in vaporous form from the ore, and then condensing the vapors into a liquid, is attended by the inconvenience that substances (as for instance water and carbonio acid) are contained in the mixture, which in the heatingv process are carried off in gaseous or vaporous form, and partly cause a reoxidation of the metal, as are also other materials (for instance hydrogenand hydrocarbons) which partly combine with the metal vapor. These are the principal causes of'the formation of metallic dust, as the impure metal does not condense in liquid form, but only precipitates as dust or powder.

Up to the present time, continuous processes have found but little adoption in technics, as the yield of liquid metal has been but small, and on the other hand the amount of dust obtained very great. Further the condensation is more complete in .proportion to the amount of zinc, and less so in proportion to that of carbonio oxid in the gas.

The process here described has for its object to effect-a perfect separation of the two products and consists essentially in the fact that the gases and vapors usuallv generated a re exhausted separately from one another, before the reduction process proper takes place. This exhausting of the gases 'and vapors can be so effected that carbonio oxid which has already been formed 1s removed at the same time, so that from fthe very inception of the process the concentrated metallic vapors reach the condensation chamber.

In the drawing are shown two methods of carrying out this invention. 5

Figure l shows in vertical axialsection an electric zinc furnace with preheater; Fig. 2 a section through the line C D of Fig. 1

the preheating zone, l through the pipe z'. V The effect of this is that and Fig. 8 a furnace with hanging electrodes, in vertical lengthwise section.

The electric furnace a (Figs. l and 2) consists of .the masonry furnace chamber the poles c1, c2 the resistance CZ, and the furnace mantle or outer shell, e. rllhe electrical current is conducted from the clamp f1 to the pole c2, and passes through the outer shell e to the clamp f2. The clamps f1, f2 are in electric connection with the poles of a transformer or other source of current. About the heating resistance CZ lies the ore mixture ,which is to be reduced. @ver the electric furnace o there is a shaft 7L for preheating and charging the ore, and through which the charge is continuously fed down to the smelting hearth. This shaft L has a charging hopper lc and an inner gas exhaust pipe z'; and is surrounded heating chamber Z.

by the annular rlhe process takes place in such manner lsible from metal, passes through the lateral pipes p1, p2 to the heating chamber Z, of the pre-heater shaft, into which air is conducted through the nozzles s1, s2, s3, s4 (F ig. Here they are burned and effect a heating of the charge g in the shaft L. From the heating chamber Zthe burner gases are conducted by the pipe t. As soon as the electric reduction process is started, the gases and vapors developed by the pre-heating are continuously exhausted away through the gas discharge pipe z' in the fore-shaft. To facilitate condensation, this exhaustion can be so effected that part' of the metal and of the carbonio oxid are led away from the reductionr zone, by which the ascending metal vapor condenses in the charge, and is again conducted with the fallingl ore to the `reduction chamber, while the together/with the other gases are conducted awa the zinc vapors which pass 'through the pipe m to' the condensation'chamber n, are free carbonio oXid gas;

developed in Y and are from re-oxidizing gases and vapors,

. richer in metal, but. poorer in carbonio oxid.

"When the heating resistance Z is used up by the process, either it mus-t be replaced or the contents-of the furnace acts as a resist-V ance, so that the. current passes lfromthe pole c1 through' the charge to the pole 02,.

Any by-metals (such as lead, silver, etc., in zinc reduction) collecting on the foor yor bottom lof the furnace, as Well as the slag, are removedfrom time to time through the tap hole fw,

inthe furnaceshown in Figh there is a vertically regulatable electrode el, about ywhich the charge -g enters the -smelting hearth; e2l being the under electrode. e While the metal vapors formed in the electric l smelting chamber areled oif With the carbonic oxid through-the pipes m1, m2, inthe direction of the arrow, to the-condensation chambers nl, n2, in which the metal con denses as liquid-,'- thecarbonic oxid gas is led o' from the latterchambers through the l pipes p1, p2 into the charging shafts h1, k.2,

iny which they are mixed Withair coming through the nozzles s, s?, and burned; While Y they give o the lead thus developed to the charge lying around the pipes. i.

About the vertical electrode c, there are arranged in the chargingeshaft ofthe elec-y tric furnace gas lexhausting pipes 1, 2,

throughl which areledo thevapors evolved from` theV chargel(mixed, if desired, With the carboniol oxid coming from `the electric reduction'chambery e -v 'lt goes Without saying, that the strength of the dierent exhausts may .be regulated .l at will, and the condensation of the zinc or j i v :Limbes in presence of A other metal thus vmade as thorough l'asfl pos-, 'i

sible. p f

The process abovev described can `*be employed for all metals Which can be'produced in liquid form.

What ll' claim asl my invention and desire y to be secured to me by Letters Patent ofthe -United States of America, is as follows.:

l. IA process for obtaining metal vapors,

especially those of zinc andlead, from ores in an electric furnace, which consistsof preheating the charge before the rdistillation process takes place, exhausting the gases and vapors developed. in the preheating zone to fre'e the metallic vapors fromgases favoring oxids or formation of metallic dust, and exhausting part of the carbon oxids and lmetal vapors ygenerated in the'distillation zone.

'2. A process. for obtaining metal vapors, especially those of zinc and lead,pfrom ores in anelectric furnace, which consists of preheating the charge4 before the distillation processl'takes place, exhausting the gases and vapors developed in the preheating zone to free the metallic vapors from gases favoring oxids or formation of metallic dus-t', exhausting part of the vcarbon oxids and metal vapors-generated in the'distillation zone, and

`Conducting the carbon oxids escaping with 

